<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>只出现一次的数字</title>
</head>
<body>
  <script>
    function fn(nums) {
      nums.sort((a, b) => a - b)
      let i = 0
      while (i < nums.length) {
        if (nums[i] === nums[i + 1]) {
          i += 3
        } else {
          return nums[i]
        }
      }
    }
    console.log(fn([2, 2, 3, 2]))
  </script>
</body>
</html>